INAPPROPRIATE GROWTH-HOP,,MONE (GH) RESPONSE TO THYROTROPIN-REI.FASING H O R M O N E (TRH) OCCURS INFREQUENTLY IN WELL-REGULATED DIABETES MELLITUS OTTAVIO GIAlVIPIETRO, MARCO FERDEGHINI, ROBERTO ~IIccOLI, GIOVANNA GREGORI, GIUSEPPE PENNO, STEFANIA BERTOLI, RENZO NAVALESI Cattedra di Malattie del Metabolismo, Istituto di Clinica Medica [Ie Centro di Medicina Nucleate, Universitgt di Pisa, Pisa Istituto di Fisiologia Clinica del CNR, Pisa, Italy
It is currently accepted that growth hormone (GH) secretion is abnormally regulated in diabetic patients -~6,54. Besides high GH levels in the basal state~.22,26. 27,54 inappropriate GH responses to many stimuli have been ascertained in diabetics. These stimuli include exercise ~8,2°.48, arginine 4,~°, glucagon I°, glucose 4.19,53, levo-dopa ~, clonidine ~6,~9, and some neuropeptides, such as the growth-hormone releasing factor (GFR) 29,4°,~l,4~ and the thyrotropin-releasing hormone (TRH) 2,~.6,9.30,50. In fact, in the last few years it has been suggested that T R H administration commonly evokes GH release in insulin-dependent diabetic (IDDM) patients, that this response is sex-related, since it is more frequent in female patients, and is related to the presence of retinopathy ~,9. After we have recently documented 14 that an inappropriate GH release to luteinizing hormone releasing hormone (LHRH) may occur in some IDDM and non-insulin dependent (NIDDM) diabetics, we report the results of the evaluation of the GH response to T R H in 30 diabetic male patients. MATERIALS AND METHODS E x p e r i m e n t a l subjects - Thirty diabetic men (23 IDDM, 7 NIDDM) were studied. Their mean age was 35 ± 2 years (range 19-58) and duration of diabetes ranged between 0.1-19 years (mean 7.1 ± 1 years); long-term metabolic control, assessed by glycated hemoglobin, was fair (HbA Z9.7 ± 0.3%). Key-words: Diabetes metlitus; Growth hormone ( GH) ; Thyrotropin-releasing hormone ( TRH).
This study was performed in the context of the Ricerca Finalizzata della Regione Toscana, and supported in part by a grant (87.00381.56) from the Italian National Research Council (CNR) and by a grant from the Ministero della Pubblica lstruzione (Ricerca Scientifica 1987). Received: November 28, 1989. Acta diabetol, lat. 27, 119-127, 1990.
119
GROVel'H-HORMONE AFTER THYROTROPIN-RELEASING
(years)
age
body weight (kg)
BMI (kg/m ~)
normals (n = 12)
2'/,4 -+ 2.3 (22-52)
68.2 4. 2 (54-85)
22.0 + 1 (19.8-24.8)
-
IDDM (n = 23)
30.6 ± 2.3 (19-51)
72.0 + 1.3 (61-88)
23.6 ± 0.4 (20.6-26.8)
7,5 ± 1.2 (0.1-19)
NIDDM (n = 7)
50.3 ± 4** (29-58)
77.5 4- 4.2 (64-94)
25.5 ± 1"* (21.6-28,7)
5.6 ± 2.5 (0.2-17)
normal range
up to ~
duration of diabetes (years)
H O t l M O N E IN D t A B E T E S
Hb,%
FPG
(%)
(mg/dl)
6.6 ± 0,2 (5.8-6.9)
retinopathy
68 ± 3
10.1 + 0,3 **0 110 4- 11"* (7.5-14.9) (70-220) 8.1 4- 0.3* (7-9.6)
97 ± 9,6" (69-140)
6-8%
65-90
5 BR, 3PR
1 BR
Tab. 1 - Clinical a n d m e t a b o l i c characteristics o f subjects studied. Data are expressed as mean 4. S E M (range). B M I = body mass index; FPG = fasting plasma glucose," BR = backgrm~nd retznopathy; PR = proliferative retinopathy, o p~O.O1 vs N[DDM; * p
It is currently accepted that growth hormone (GH) secretion is abnormally regulated in diabetic patients -~6,54. Besides high GH levels in the basal state~.22,26. 27,54 inappropriate GH responses to many stimuli have been ascertained in diabetics. These stimuli include exercise ~8,2°.48, arginine 4,~°, glucagon I°, glucose 4.19,53, levo-dopa ~, clonidine ~6,~9, and some neuropeptides, such as the growth-hormone releasing factor (GFR) 29,4°,~l,4~ and the thyrotropin-releasing hormone (TRH) 2,~.6,9.30,50. In fact, in the last few years it has been suggested that T R H administration commonly evokes GH release in insulin-dependent diabetic (IDDM) patients, that this response is sex-related, since it is more frequent in female patients, and is related to the presence of retinopathy ~,9. After we have recently documented 14 that an inappropriate GH release to luteinizing hormone releasing hormone (LHRH) may occur in some IDDM and non-insulin dependent (NIDDM) diabetics, we report the results of the evaluation of the GH response to T R H in 30 diabetic male patients. MATERIALS AND METHODS E x p e r i m e n t a l subjects - Thirty diabetic men (23 IDDM, 7 NIDDM) were studied. Their mean age was 35 ± 2 years (range 19-58) and duration of diabetes ranged between 0.1-19 years (mean 7.1 ± 1 years); long-term metabolic control, assessed by glycated hemoglobin, was fair (HbA Z9.7 ± 0.3%). Key-words: Diabetes metlitus; Growth hormone ( GH) ; Thyrotropin-releasing hormone ( TRH).
This study was performed in the context of the Ricerca Finalizzata della Regione Toscana, and supported in part by a grant (87.00381.56) from the Italian National Research Council (CNR) and by a grant from the Ministero della Pubblica lstruzione (Ricerca Scientifica 1987). Received: November 28, 1989. Acta diabetol, lat. 27, 119-127, 1990.
119
GROVel'H-HORMONE AFTER THYROTROPIN-RELEASING
(years)
age
body weight (kg)
BMI (kg/m ~)
normals (n = 12)
2'/,4 -+ 2.3 (22-52)
68.2 4. 2 (54-85)
22.0 + 1 (19.8-24.8)
-
IDDM (n = 23)
30.6 ± 2.3 (19-51)
72.0 + 1.3 (61-88)
23.6 ± 0.4 (20.6-26.8)
7,5 ± 1.2 (0.1-19)
NIDDM (n = 7)
50.3 ± 4** (29-58)
77.5 4- 4.2 (64-94)
25.5 ± 1"* (21.6-28,7)
5.6 ± 2.5 (0.2-17)
normal range
up to ~
duration of diabetes (years)
H O t l M O N E IN D t A B E T E S
Hb,%
FPG
(%)
(mg/dl)
6.6 ± 0,2 (5.8-6.9)
retinopathy
68 ± 3
10.1 + 0,3 **0 110 4- 11"* (7.5-14.9) (70-220) 8.1 4- 0.3* (7-9.6)
97 ± 9,6" (69-140)
6-8%
65-90
5 BR, 3PR
1 BR
Tab. 1 - Clinical a n d m e t a b o l i c characteristics o f subjects studied. Data are expressed as mean 4. S E M (range). B M I = body mass index; FPG = fasting plasma glucose," BR = backgrm~nd retznopathy; PR = proliferative retinopathy, o p~O.O1 vs N[DDM; * p
